Strategic Approaches to Filing International Patents via the PCT

Filing a patent in one country is complex enough. Filing it across multiple countries – while managing costs, timelines, and legal requirements in each jurisdiction – can feel overwhelming. The Patent Cooperation Treaty (PCT), administered by the World Intellectual Property Organization (WIPO), was designed to simplify exactly this. But using the PCT effectively isn’t just about knowing the procedure – it’s about knowing the strategy. Applicants who approach PCT filings with a clear plan from day one are better positioned to secure broad protection while managing costs and timelines efficiently.

The PCT system in brief 🔗

Before diving into strategies, a quick recap: the PCT allows an applicant to file a single international application that effectively preserves their filing date across all 158 PCT member states. It does not grant a patent directly – that still happens at the national or regional patent office level. What the PCT does is buy time and consolidate the early-stage process: one application, one language, one set of fees at the international phase. After approximately 30 months from the earliest priority date, the applicant must enter the “national phase” and pursue patents individually in each target country.

Understanding this framework is what makes the following strategies meaningful.

Strategy 1: The provisional filing route 🔗

A very common and cost-effective strategy, especially for early-stage inventors and startups, is to begin with a provisional patent application at a national patent office. In India, this means filing a provisional specification under the Patents Act, 1970, with the Indian Patent Office (IPO). A provisional filing establishes the priority date – the critical date from which novelty is assessed – without requiring a complete, fully drafted specification.

Once the provisional is filed, the applicant has 12 months to file a complete specification. Within that same 12-month window, they can also file a PCT application claiming the priority of the provisional. This combination – provisional first, then PCT – is strategically powerful. A provisional application will not be subjected to substantive examination and will not be published, which gives the applicant breathing room to refine the invention, conduct market research, or secure funding, all while holding a priority date.

The key caution here: the provisional must contain sufficient detail about the invention. Any information not included in the provisional which is presented later will not be given the benefit of the provisional filing date. A poorly drafted provisional can effectively shrink your protection – so it must be taken seriously, not treated as a placeholder.

Strategy 2: Direct PCT filing as the first application 🔗

Some applicants choose to skip the provisional stage entirely and file a PCT application as their first filing. This is particularly suitable when:

• The invention is fully developed and ready for a complete specification,
• The applicant has identified from the outset that multi-country protection is the goal, and
• There is no pressing need to secure a domestic patent quickly.

Filing PCT directly as the priority application has its advantages. The PCT system allows applicants to file a single international application to seek protection in over 158 countries, and from this single filing date, the 30-month clock begins. This gives the applicant a long window – nearly two and a half years – to evaluate where they want to pursue patents, before incurring the much higher costs of national phase entries.

This approach works well for larger entities or those with strong IP budgets who are certain of international commercialization. For Indian applicants, the PCT application can be filed electronically with the Indian Patent Office as Receiving Office (RO/IN) through the ePCT module.

Strategy 3: PCT filing after a national non-provisional application 🔗

A third common route is to first file a complete (non-provisional) national patent application – in India, a complete specification under the Patents Act – and then file a PCT application within 12 months of that national filing, claiming its priority date. This strategy is favoured when:

• The applicant wants domestic examination to begin quickly in India, and
• The applicant also wants to keep international options open without committing to individual country filings immediately.

Filing PCT after a national application defers the major international filing costs by 18 months compared to direct country-by-country filing – a period referred to as the international phase. This is a significant financial advantage, particularly for startups that need to test market traction before committing to multi-jurisdictional patent expenditure.

Selecting the right International Searching Authority (ISA) 🔗

One of the most consequential decisions in PCT strategy is the choice of ISA. The ISA conducts a prior art search and issues an International Search Report (ISR) and a Written Opinion (WO) on the invention’s patentability. While these are non-binding on national offices, they carry significant practical weight during national phase prosecution.

The ISAs available to an applicant depend on which Receiving Office they file through. For Indian applicants filing through RO/IN, the competent ISAs include the Indian Patent Office (IPO), Austrian Patent Office, Australian Patent Office, European Patent Office (EPO), China National Intellectual Property Administration (CNIPA), USPTO, and others.

Choosing the Indian Patent Office as ISA 🔗

The Indian Patent Office has functioned as an ISA and IPEA since October 2013. For Indian applicants, choosing IPO as the ISA comes with certain advantages: lower search fees compared to offices like the EPO or USPTO, and the added benefit that choosing IPO as ISA or IPEA qualifies the applicant for expedited examination when entering the Indian national phase. This is particularly useful for DPIIT-recognized startups looking to fast-track Indian patent prosecution.

Choosing the EPO as ISA 🔗

The EPO is widely regarded as the gold standard for PCT searches. Its examiners read English, German, and French, and often additional languages, resulting in thorough prior art searches. A positive Written Opinion from the EPO tends to carry strong persuasive weight before national offices in Europe. However, the EPO has notable limitations: it does not act as ISA for applications where claims relate to business methods, and it is generally stricter on unity of invention – meaning multiple inventions in one application can attract additional search fees.

USPTO and Korean IP Office as ISA 🔗

For technology-heavy inventions in areas like software, electronics, or telecommunications, the USPTO and the Korean Intellectual Property Office (KIPO) are frequently chosen. The USPTO, EPO, Japan, Korea, and China are part of the IP5 Patent Prosecution Highway (PPH) – a programme that allows applicants to leverage a positive search result from one IP5 office to accelerate examination in others. If an applicant’s target markets include the US, Japan, and Korea, selecting an IP5 ISA can strategically shorten examination timelines across multiple jurisdictions.

Key factors to weigh when selecting an ISA 🔗

The selection decision should consider: fees (search fees vary significantly between ISAs); language capabilities of the searchers, especially if relevant prior art exists in non-English literature; subject matter (the EPO will not search business methods; the IPO has growing strength in pharmaceuticals and chemicals); unity of invention strictness (stricter ISAs can lead to additional fees); timeliness (an ISR arriving after the 30-month deadline is of limited use); and PPH eligibility for target countries.

Leveraging Chapter II: International Preliminary Examination 🔗

After receiving the ISR and Written Opinion, applicants have another strategic option: filing a Demand for International Preliminary Examination (IPE) under Chapter II of the PCT. By default, examination under Chapter I happens without any direct interaction between the applicant and the examiner. Chapter II changes this – it allows dialogue between the applicant and the examiner, giving the applicant an opportunity to amend claims and address objections before entering the national phase.

Chapter II is particularly valuable when the initial search report is negative – it allows the applicant to strengthen their position before national phase entry rather than fighting the same battles repeatedly in each country. The result of this process is the International Preliminary Report on Patentability (IPRP) under Chapter II, which, if favourable, can significantly ease prosecution across target jurisdictions.

PCT vs. direct Paris Convention filings: choosing your route 🔗

The “direct filing” route under the Paris Convention involves submitting individual patent applications directly to the patent office of each country from which protection is sought. If protection is needed in only two or three countries, direct filing is often more cost-effective – there’s no PCT filing fee to pay, and examination begins faster. If protection is required in more than a few countries, however, the PCT route is generally more economical because it consolidates the early-stage process and defers national phase costs by up to 30 months.

It is also possible to pursue both simultaneously – filing a PCT application while also filing direct national applications in high-priority markets. This hybrid approach allows examination to begin quickly in key jurisdictions (like the US or EU) while preserving broader international options through the PCT.

Practical considerations for Indian applicants 🔗

Indian applicants benefit from a fee structure that recognizes different entity categories. Indian applicants typically pay lower fees at the Indian Patent Office as ISA compared to major foreign ISAs. WIPO also provides fee reductions of 90% on international filing fees for natural persons from least developed countries, and standard fee reductions for startups and small entities apply broadly.

One important procedural point: under Indian law, an Indian resident cannot file a patent application abroad without first filing in India or obtaining a foreign filing licence. This requirement under the Patents Act means that PCT strategy for Indian applicants must always begin with compliance on this front before proceeding internationally.

Finally, the national phase entry in India for foreign PCT applicants – or for Indian applicants re-entering India – has a 31-month deadline from the priority date, one month longer than the standard 30 months applicable in most other PCT member states.

Putting strategy into practice 🔗

There is no one-size-fits-all approach to PCT filing. The right strategy depends on the stage of invention development, commercial objectives, target markets, budget, and competitive landscape. A pharmaceutical startup in Mumbai looking to protect a drug candidate across regulated markets like the US, EU, and Japan will take a very different approach from a solo inventor in Bengaluru filing a software-adjacent invention. What remains constant is that every decision made in the PCT process – from the type of first filing to the choice of ISA – has downstream consequences that affect both the cost and the strength of the resulting patent portfolio.

Applicants who treat PCT filing as a strategic exercise rather than a procedural one are the ones who extract maximum value from the system.

What do you think? If you were advising an Indian startup on whether to begin with a provisional filing or go directly to a PCT application, which factors would weigh most heavily in your recommendation – and does the answer change depending on whether the startup is in biotech versus software?

References

1. https://www.wipo.int/pct/en/faqs/faqs.html
2. https://patentgc.com/patent-application-process/
3. https://www.rkdewan.com/blogs/strategic-patent-filing-india-national-pct-guide/
4. https://ipindia.gov.in/isaweb/
5. https://www.spruson.com/use-of-the-pct-system-and-advantages-and-benefits-of-international-preliminary-examination-ipe/
6. https://www.ipandlegalfilings.com/services/global-patent-filing/
7. https://www.patents.co.uk/news/2023/which-international-searching-authority-should-you-choose-a-guide-for-non-european-applicants
8. https://patentattorneyworldwide.com/us/patent-co-operation-treaty-pct-application/
9. https://www.seedip.com/posts/strategic-considerations-for-international-patent-filings-exploring-the-pct-vs-direct-filing-routes-by-seed-ip-partner-bobby-soltani
10. https://www.zatapult.com/pct-applications/